Compounds proportions

These consequences are, that substances act in the compound proportion of the quantity in the sphere of action, and of the affinity with which they are endued that the latter may be compensated by the former, and that the chemical action of each is proportional to the degree of saturation which it produces. I have distinguished by the term chemical mass, or mass, the quantities as determined by an equal degree of saturation, which quantities are consequently relative to their capacity of saturation. ... 

The extent of decomposition is in compound proportion to the affinities and the surfaces of the poles. It is proportional to the quantity of electrical conductivity. 

Two new compounds, proportional to each other, in which case an element has been partially separated. 

A 98% conversion efficiency has been achieved at 1.5 atmospheric pressure of CO2 and 10% excess of water, while the yield was 85% only when stoichiometric amounts of water and carbon dioxide were used. No isotopic fractionation has been noted when 5 to 10% excess of water has been used in the reaction in equation 5. Doubly labelled methane has been used in simultaneous analysis of and both in the atmosphere and in environmental carbon dioxide as well as in analysis of and H-labelled organic compounds. Proportional counters filled with methane possess very good counting properties and there is no need to add any inactive counting gas. and tritium-labelled methanes have also been produced" by pyrolysis of sodium acetate in molten sodium hydroxide (equation 6) ... 

In compound liquids the relative magnitude of the chemical decomposition is in the compound proportion of the degree of affinity of the components to one another and the surface of contact with the conductor. Thus, a stronger combination may often be separated, whilst a weaker remains undecomposed because it does not touch the conductor with a sufficient surface. The stronger the affinity of the components for one another the greater must be the surface of contact, and conversely. 

These statements, which contain the whole of Dalton s chemical atomic theory, were arrived at completely in September to October 1803, and remained unchanged in all Dalton s later publications. The symbolic representation of the compositions of compounds used by Dalton (his symbol law ) contained implicitly the laws of definite, multiple, and reciprocal proportions, and Dalton does not give verbal statements of these laws. It was asserted that the law of constant proportions would be a better name than the law of definite proportions and that a further law of compound proportions (vi) is necessary, stating that the combining weight of a compound is the sum of the combining weights of its components, which does not follow from the other laws of chemical combination. 

Costa M, Mollenhauer HH (1980) Carcinogenic activity of particulate nickel compounds proportional to their cellular uptake. Science 209 515-517 De Flora S, Wetterhahn KE (1989) Mechanism of chromium metabolism and genotoxicity. Life Chem Rep 7 169-244... 

The addition of antioxidants can alleviate the photodegradation of both wood fiber and thermoplastics. Peng et al. [125] combined two kinds of antioxidants, namely antioxidant 1010 (AO-lOlO, hindered phenols) and antioxidant 168 (AO-168, phosphite), and then made WF/PP composites at different compound proportions. The chemical structures of the two antioxidants are given in Fig. 24. The compound systems showed a synergistic effect on maintaining the surface color and flexural properties of the composites, especially at the ratio of 1 5 (AO-lOlO AO-168). 

Table 5 Individual Flavor Compounds Proportions (Percentage) of the Total Volatile Flavor Released from Sunflower Oil Under Dynamic Headspace Conditions ...

The most important reaction of the diazonium salts is the condensation with phenols or aromatic amines to form the intensely coloured azo compounds. The phenol or amine is called the secondary component, and the process of coupling with a diazonium salt is the basis of manufacture of all the azo dyestuffs. The entering azo group goes into the p-position of the benzene ring if this is free, otherwise it takes up the o-position, e.g. diazotized aniline coupled with phenol gives benzeneazophenol. When only half a molecular proportion of nitrous acid is used in the diazotization of an aromatic amine a diazo-amino compound is formed. 

NH3) are of great commercial importance practically all modem explosives contain high proportions of ammonium nitrate or organic nitro-compounds. Nitrates are also employed as fertilizers. 

Table 5.24 shows that these specific pollutants are present only in small proportions (about 8%) of the total organic compounds emitted by the motor, but they are particularly feared because of their incontestable toxicity. Prominent among them is benzene. 

The reaction mechanism for these products is not clearly understood, but the introduction of organo-metallic compounds (barium or iron salts in colloidal suspension) has been shown to have a beneficiai action on the combustion of diesel fuel in engines and reduce smoke. However, these products cause deposits to form because they are used in relatively large proportions (on the order 0.6 to 0.8 weight %) to be effective. 

Olefins are uncommon in crude oils due to the high chemical activity of these compounds which causes them to become saturated with hydrogen. Similarly, acetylene is virtually absent from crude oil, which tends to contain a large proportion of the saturated hydrocarbons, such as the alkanes. 

X-ray photoelectron spectroscopy (XPS), also called electron spectroscopy for chemical analysis (ESCA), is described in section Bl.25,2.1. The most connnonly employed x-rays are the Mg Ka (1253.6 eV) and the A1 Ka (1486.6 eV) lines, which are produced from a standard x-ray tube. Peaks are seen in XPS spectra that correspond to the bound core-level electrons in the material. The intensity of each peak is proportional to the abundance of the emitting atoms in the near-surface region, while the precise binding energy of each peak depends on the chemical oxidation state and local enviromnent of the emitting atoms. The Perkin-Elmer XPS handbook contains sample spectra of each element and bindmg energies for certain compounds [58]. 

These substances, having the formula CjHjNHCONH, and OC(NHCjH6)j respectively, are both formed when an aqueous solution of urea and aniline hydrochloride is heated. Their subsequent separation is based on the fact that diphenylurca is insoluble in boiling water, whereas monophenylurea is readily soluble. The formation of these compounds can be explained as follows. When urea is dissolved in water, a small proportion of it undergoes molecular rearrangement back to ammonium cyanate, an equilibrium thus being formed. 

The breaking up of azeotropic mixtures. The behaviour of constant boiling point mixtures simulates that of a pure compound, because the composition of the liquid phase is identical with that of the vapour phase. The composition, however, depends upon the pressure at which the distillation is conducted and also rarely corresponds to stoichiometric proportions. The methods adopted in practice will of necessity depend upon the nature of the components of the binary azeotropic mixture, and include —... 

In addition to the use of a melting point determination as a criterion of purity, an equally valuable application is for the identification of oiganic compounds. If the melting point is known within one degree, the major proportion of possible substances is immediately eliminated from consideration. The study of the general chemical properties of the compound and a mixed melting point determination (Section 1,17) will largely establish the identity of the compound. 

The theory underlying the removal of impurities by crystaUisation may be understood from the following considerations. It is assumed that the impurities are present in comparatively small proportion—usually less than 5 per cent, of the whole. Let the pure substance be denoted by A and the impurities by B, and let the proportion of the latter be assumed to be 5 per cent. In most instances the solubilities of A (SJ and of B (/Sb) are different in a particular solvent the influence of each compound upon the solubility of the other will be neglected. Two cases will arise for an3 particular solvent (i) the impurity is more soluble than the compound which is being purified (/Sg > SA and (ii) the impurity is less soluble than the compound Sg < S ). It is evident that in case (i) several recrystallisations will give a pure sample of A, and B will remain in the mother liquors. Case (ii) can be more clearly illustrated by a specific example. Let us assume that the solubility of A and 5 in a given solvent at the temperature of the laboratory (15°) are 10 g. and 3 g. per 100 ml. of solvent respectively. If 50 g. of the crude material (containing 47 5 g. of A and 2-5 g. of B) are dissolved in 100 ml. of the hot solvent and the solution allowed to cool to 15°, the mother liquor will contain 10 g. of A and 2-5 g. (i.e., the whole) of B 37-5 g. of pure crystals of A will be obtained. 

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